1. Field of the Invention
This invention relates to a composition for ferroelectric thin film formation for use in forming a ferroelectric thin film, and also to a ferroelectric thin film, and a liquid-jet head.
2. Description of the Related Art
A ferroelectric thin film containing a crystal, typified by lead zirconate titanate (PZT), has spontaneous polarization, a high dielectric constant, an electro-optic effect, a piezoelectric effect, and a pyroelectric effect, and thus finds application in the development of a wide variety of devices such as piezoelectric elements. As methods for forming such a ferroelectric thin film, the MOD method, the sol-gel process, CVD (chemical vapor deposition), and sputtering, for example, are known (e.g., see Japanese Patent Application Laid-Open No. 2000-119022, “Prior Art”). A ferroelectric thin film is formed, for example, by coating a composition for ferroelectric thin film formation (a colloidal solution) on a subject material, then drying and firing the coating.
It is generally preferred that the ferroelectric thin film be a dense film. In recent years, a demand for such a dense film has been growing gradually. The composition for ferroelectric thin film formation, which is used to form a ferroelectric thin film, shows a tendency toward relatively low storage stability. The ferroelectric thin film is used for a piezoelectric element, etc., as mentioned above. If its film quality is poor, the piezoelectric characteristics of the piezoelectric element having the ferroelectric thin film fluctuate. In a liquid-jet head having the piezoelectric element as a piezoelectric actuator, moreover, such fluctuations in the piezoelectric characteristics of the piezoelectric element may cause variations in liquid ejection characteristics.